Speakeasy
Takes an OpenAPI spec and generates polished, type-safe client SDKs across multiple languages, Terraform providers, and MCP servers for AI agent integration. Handles pagination, retries, webhooks, and streaming out of the box. Increasingly positioning itself as the API platform for the agent era.
Stainless
Accepts an OpenAPI spec and produces high-quality, idiomatic SDKs that feel hand-written across TypeScript, Python, Go, Java, Kotlin, Ruby, PHP, and C#. GitHub integration auto-regenerates SDKs when the spec changes. The team behind OpenAI, Anthropic, Cloudflare, and Meta's official SDKs.